1. Field of the Invention
The invention relates to the field of coating applicators and, in particular, to a touch-up applicator for reaching remote locations.
2. Description of Related Art
It is often necessary to touch-up previously coated structures because small areas are sometimes missed or the coating is damaged during handling. Sometimes the individual components of the structure are coated separately and are assembled with fasteners that will require protective coatings. However, touch-up after assembly requires that the coating applicator assembly be small and provide accessibility to hard to reach close out areas.
Syringe type applicators are old in the art. Examples can be found in U.S. Pat. No. 1,711,516 xe2x80x9cPlunger Shaving Brushxe2x80x9d by M. Alland; U.S. Pat. No. 3, 519,364 xe2x80x9cApplicatorxe2x80x9d by A. Truhan; U.S. Pat. No. 4,029,422 xe2x80x9cDispenser For Air Drying A Liquidxe2x80x9d by E. J. Pillsbury; U.S. Pat. No. 4,599,008 xe2x80x9cFingernail Polish Capsule And Plungerxe2x80x9d by P. J. Furlong, et al.; and U.S. Pat. No. 5,269,684 xe2x80x9cAdjustable Brush Delivery Tip With Secondary Flow Pathxe2x80x9d by D. E. Fischer, et al. All these applicators have a syringe and a fixed dispensing nozzle. Having a fixed dispensing nozzle limits its use to areas that have sufficient space for both the syringe and applicator nozzle and operators hands.
This problem has long been recognized. For example having a brush attached to a flexible hose connected to a reservoir of liquid is an old concept. For example, U.S. Pat. No. 6,048,583 xe2x80x9cMethod Of Applying A Liquid Protectorantxe2x80x9d by R. L. Waddell disclosed a automobile tire coating apparatus wherein the dispensing brush, with gripping handle and actuation lever, attached by a flexible line to a tank. Of course, portable fire extinguishers have used nozzles mounted on the end of flexible tubes.
However, one of the major problems in doing touch-up coating of aircraft structures, is that the coating material must be accurately applied in a very limited space. Thus it is sometimes necessary to have the coating material container physically separated from the applicator. Furthermore, one must be able to adjust the position of applicator to reach tight positions. In addition, if the coating applicator is going to be used with two-part coating materials, containing a resin and catalyst, it is unlikely that it can be reused, thus cost becomes a factor.
Thus, it is a primary object of the invention to provide a coating applicator assembly for use in restricted areas.
It is another primary object of the invention to provide a coating applicator assembly for use in restricted areas wherein the container for the coating is located some distance from the applicator.
It is a further object of the invention to provide a coating applicator assembly for use in restricted areas wherein the applicator positioning is adjustable.
It is a still further object of the invention to provide a coating applicator assembly that is low in cost.
It is a further object of the invention to provide a non-spray applicator that does not atomize or produce hazardous air pollutants.
The invention is a coating applicator assembly for touch-up coating of a structure. In detail, the invention includes a syringe for containing the coating material of the type having a plunger at a first end for expelling the coating material out a second end. A flexible tube is coupled by its first end to the second end of syringe. A hollow handgrip is connected by a first end to second or opposite end of the flexible tube. A semi-flexible tube is coupled to its first end to the opposite or second end of the hollow handgrip. By, semi-flexible is meant that the tube can be bent into different shapes, but once bent will remain in that shape. A coating applicator is coupled to the second or opposite end of the semi-flexible tube. The coating applicator can be a brush or a foam tip of the type that can imbibe coating material and apply it to the structure.
Preferably, the syringe, flexible tube, and handle are made of plastic materials. A syringe having a 10 cubic centimeter volume is preferred because it can easily be handled using one hand. The internal diameter should of the passage way through the flexible tube and handle should be around 0.0625 inch. Of particular importance is the material used for the semi-flexible tube. Here it has been found that a semi-flexible tube is preferably made from soft metal such as aluminum, brass or copper tubing coated or covered with plastic. The internal diameter should be around 0.0625 inch with an outer diameter of 0.125 inch. The use of plastic materials will keep the manufacturing costs to a minimum. This is essential, since one of its primary applications is the dispensing of two component-coating materials. That is one containing a resin premixed with a catalyst. This requires storing at low-temperatures after loading of syringe, providing a shelf life of up to six months. Thus in many instances the syringe, flexible tubing and handle are usable after the resin sets. However, the semi-flexible tubing is recycled.
An alternate version of the invention attaches the syringe directly to the semi-flexible tube. This has the advantage of allowing one hand operation, which in certain situations can be advantageous.
In another embodiment a housing is provided having an open first end adapted to receive said syringe and a closed off second end, with the second end having an aperture there through. A valve is mounted in the second end of the housing for controlling the flow of coating material through the aperture from the syringe. The housing further includes a plunger biasing assembly that bias the plunger of the syringe toward the second end thereof. Thus when said syringe is installed in the housing, the plunger biasing assembly forces the plunger toward the second end of the syringe forcing coating material out the outlet port thereof and into the aperture in the housing. The valve controls the flow there through. Semi-flexible tube can be coupled directly to the housing or via the flexible line and handle. The use of the housing with its plunger biasing assembly and valve is far easier to use, since pressure is always available.
The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages thereof, will be better understood from the following description in connection with the accompanying drawings in which the presently preferred embodiments of the invention are illustrated by way of examples. It is to be expressly understood, however, that the drawings are for purposes of illustration and description only and are not intended as a definition of the limits of the invention.